1. Field of the Invention
This invention relates in general to magnetic recording and more particularly to improved apparatus for providing tracking control during the playback of recorded signal information.
2. Description Relative to the Prior Art
There is a trend toward the packing of greater and greater amounts of data on magnetic tape. Implicit in such trend is the requirement that data tracks on such tape be as narrow, and as closely packed together, as possible. With a high-track-density multitrack magnetic head, say of a type that provides 400 tracks per inch, the tracks would be 0.0020", given guardbands of 0.0005". It is clearly of concern, therefore, that during playback of recorded information, the information so recovered be from the correct track, and not from a neighboring one.
It is known in the art to record tracking control signals on a magnetic tape as a vehicle for preventing head-to-tape wander during playback of information recorded on the tape. Representative prior art in this connection may be found in U.S. Pat. No. 3,474,432 which depicts the use of various prerecorded frequencies in respective tracks, the signals being mixed in such a way as to cause head position error signals to be generated in response to head-to-tape wander. Similarly, more recent1y issued U.S. Pat. No. 4,258,398 calls for the use of paired pre-recorded tracks as signal-sources for head orienting/positioning in connection with a multitrack configuration. Other and varied tracking control techniques have been demonstrated and taught in the art, albeit that such techniques exhibit less than optimally tight-control and, accordingly, are wanting when it comes to the matter of sensitivity.